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Discussion Starter #1 (Edited)
I am setting up a soil-based tank and would like to know what micronutrient source I can add to it so that I do not have to frequently dose traces?

I have done some reading on soil-based tanks. I will boil the top soil to remove the NH4/urea. But from what I could find online, people are saying that soil are usually low in micronutrients, particularly iron. So, I am wondering what I can add to correct this deficiency?

I was thinking of adding laterite but that only adds iron. What about the other micronutrients?

Also, I don't want to mix the soil with gravel since the top soil mix I plan on using is the cheap kind from Home Depot which is primarily sand anyway. Is this ok? Is it going to turn the tank into a stinking mess since a lot of posts I've read suggest only 1" or so?

Oh another thing: how long do I have to boil the soil to remove all of the NH4/urea?

This is a low light/low maintenance tank. Thanks for all your help. :)

Premium Member
3,966 Posts

In my opinion, what you are planning is very difficult to implement. It is hard to control the amount of nutrients leaching out of the soil. It also tends to taint your water brown as some of it will dissolve.

You should read Steve Pushak's site especially the soil soup article. Do a search in Google for him and you'll come up with the URL as I can't remember it offhand.

I found a qoute on my computer from our own Paul K where he describes soil soup and how to make it:

"The "soil-soup" method where soil is collected and water is slowly added with much mixing until you have something like thick soup, which is then run through window screening or a rice strainer, produces a safe product. The screening filters out all the roots, worms and other critters, and other "raw" pieces of organic matter that might cause a large oxygen demand. About a quarter inch to a half inch of the soup is placed in the bottom of the tank or planting tray and covered with about a half to one inch of gravel. Water can be added with precautions to prevent stirring up the gravel, and almost no cloudiness will develop. The gravel can be put on top of the soup, and then everything can be allowed to dry out. The soup turns quite hard, but when water is added, it gets soft again, and the plants seem to grow just as well. If the soup has been allowed to dry out, the chances of any cloudiness developing when water is added are much less. The soup is relatively low in organic matter, and I have found that, when a tray becomes packed with roots, low-level iron deficiency develops, and additions of soluble
iron stimulate growth. Soil-peat mixtures or soil-manure mixtures beneath gravel seem to be able to supply iron for a longer time. I have not seen any tannins come from soil-soup, but I have seen tannins get into the water from soil-manure and soil-peat mixtures. A water change gets rid of them, and they don't seem to come back."
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